A steering column device has been known in which an outer column and an inner column are axially slidably fitted together allowing a telescopic position to be adjusted and, at a time of secondary collision, a shock load to be absorbed. Generally, in such a steering column device, an axial slit is formed in the outer column; and the outer column is clamped from its outer periphery causing the outer column to be elastically deformed in its slit portion, so that, when the vehicle is in normal operation, the inner column is clamped to be unmovable relative to the outer column (Patent Document 1).
Whereas such a steering column device having a slit formed in an outer column is advantageous in that the outer column can be elastically deformed in its slit portion with ease to securely clamp an inner column, it has a problem that the slit decreases the rigidity and strength of the outer column itself. Particularly, in cases where the steering column device has a structure which allows a steering lock device to be attached to the outer column, the rigidity of steering locking by the steering lock device becomes inadequate.
Patent Document 1: Japanese Unexamined Patent Publication No. 2003-2211